'I guess I'm up for grabs now'

Last week you would have passed her in the street. Next week British actress Sophie Okonedo will be heading up the red carpet hoping for an Oscar. It's all a long way from selling clothes at Portobello Market

When news broke of Sophie Okonedo's surprise Oscar nomination as Best Supporting Actress for Hotel Rwanda, it was a genuine cause for celebration. A Rada-trained actress in her mid-thirties who is most definitely not part of the luvvie establishment (despite acclaimed performances with the RSC and the Royal Court), Okonedo is the first black British actress to be nominated since Marianne Jean-Baptiste in 1996.

Newspapers fell over themselves to profile Okonedo and a common theme began to emerge. Words such as 'Cinderella', 'tragic' and 'sink estate' cropped up regularly - alluding to Okonedo's early upbringing on north London's Chalkhill estate. Her mixed-race heritage was picked over (her mother is Jewish, her father Nigerian); ditto her parents' separation when she was five. Tabloid reporters stalked her seven-year-old daughter at school and harassed her 90-year-old grandmother.

While the American media celebrates its hot young stars, one senses that the media here 'punish' young British women who do well. 'For a moment I thought of hopping on a plane back to America,' Okonedo admits. 'But I'm pretty secure about who I am. Anything that's truthful I'm not ashamed of. I suppose I have to look at it from their point of view because I never really did interviews before. I could get away with it because there was always a more famous actor in everything I did. But I knew it would be necessary for Hotel Rwanda, so I changed my view. I guess I'm up for grabs now, so long as they don't upset my daughter - I'm quite strict about that.'

Depressingly little has been made of Okonedo as a serious artist. Part of the 'problem' is her chameleon quality as a performer. For several years she has been threatening to become a star. As the prostitute with a heart in Stephen Frears's Dirty Pretty Things, she stole the film from Audrey Tautou. She was luminous as a single mother caught in the poverty trap in Tony Marchant's TV drama Never Never, and genuinely scary as a bigamist in BBC1's Clocking Off. For a beautiful woman, Okonedo can play plain, ordinary, stubborn. What all her roles have in common is authenticity. 'She is just so talented,' raves Frears, who cast her in Dirty Pretty Things. 'She plays characters who are struggling with life, but who can also be funny about it, rather than just a victim.'

Last Saturday she made a triumphant appearance at the Baftas in a black boned-bodice Robert Cavalli gown. 'I've always thought of her as tough and gutsy, someone who lives on their wits,' says Frears, 'and of course that's what's so interesting about her turning into this wonderful beauty.' I ask him about the tabloid obsession with her childhood. 'She's been very, very dignified about it all. Whenever she talks to me about it, she's very funny. She's so cheeky and outrageous.'

If anything, Okonedo seems keen to play down her new glamour status. 'You think, "I'm not going to get known for wearing dresses, am I!"' she mock-groans. This is her first proper interview since the nomination. She's been in Berlin filming the sci-fi film Aeon Flux with Charlize Theron and Frances McDormand, which accounts for her amazing physique. 'I'm an action-y person,' she laughs. 'I do lots of fighting and kick-boxing and back-flipping.'

She is dressed down in black cords and a fleecy coat. Her hair, usually a whoosh of static, is carefully styled to show off those killer cheekbones. When she smiles, she looks about six. Several recent profiles have hinted at 'prima donna' behaviour on the set of Hotel Rwanda (er, wouldn't you occasionally show strain shooting a film about genocide?), but she seems remarkably chilled and friendly - especially since another lurid story has just appeared in the Mail on Sunday about her family.

The paper has 'helpfully' tracked down her father in Lagos, where he lives with his second family. All the usual tabloid elements are there: errant black father, brave white single mother and, of course, the plucky young actress who defies the odds to win through. Which leads you to wonder: why do all mixed-race women have to be portrayed as troubled (think Kelly Holmes, Ms Dynamite, Halle Berry)?

Okonedo will not discuss her father. 'I haven't read the article,' she says flatly, adding: 'It's quite ... shocking. I didn't quite realise people would dig up things so much. By God I wouldn't have wanted this to happen 15 years ago. There's no way I could have handled it. Don [Cheadle, her co-star in Hotel Rwanda] just couldn't believe it when I told him, and you imagine that sort of thing happens all the time in America.'

Hotel Rwanda is a low-budget miracle (Cheadle is nominated for Best Actor and it's up for Best Original Screenplay). It tells the true story of hotel manager Paul Rusesabagina (Cheadle) and his wife Tatiana (Okonedo) who housed more than 1,200 Tutsi refugees during the Rwanda genocide. Although the film does not spare us the full horror - or the fact that the international community turned a blind eye - it is far from worthy. Like Schindler's List, you leave the cinema feeling both humbled and empowered.

Okonedo says they were determined to make an entertainment thriller that would reach the widest possible audience. 'We weren't out to make a documentary; we wanted to make drama. It's essential that you're compelled by the story and not repulsed. And the relationship between Paul and Tatiana is very important. I think it's amazing they didn't go crazy.'

How did she and Cheadle build up chemistry? 'To be honest, I think you either have it or you don't. Luckily, Don and I got on very well, we're very close friends now, and I think the world is going to see him completely differently as an actor after this film. I also know he has plans to direct.'

As research, Okenodo read Fergal Keane's Season of Blood. She also spent time with Tatiana, who now lives in Brussels with Paul and their children. 'I wanted to know about how she met Paul and her life in Kigali as a mother before the genocide. We've had quite a few nights chatting over red wine.'

The joy of Hotel Rwanda is that we get two African leads (the white liberals are all in supporting roles), played as flesh-and-blood human beings. 'It translates totally, doesn't it?' observes Okonedo. 'I was very keen to make that leap from London girl to Rwandan housewife, but I felt the story we were telling was so human that it relates to almost any country. When the reviews came out in America, I thought, "I hope it's not a sympathy vote for an all-black film", because you want people to genuinely engage with the story.'

The film makes clear the West's own responsibility for setting Hutus against Tutsis, based on entirely arbitrary physical characteristics - such as longer noses or darker skin. 'I found that very helpful because before I started doing the film I had this impression of African groups fighting over some age-old tribal blah-di-blah. Then you think, "Ah right, divide and rule, that's how it started." I hope after seeing it people will have a different attitude to asylum seekers.'

Okonedo was born in 1969. Her father, a government worker, left the marital home to return to Nigeria when she was five, leaving her mother to raise Sophie. She left school at 16 to work on a clothing stall at Portobello Market, then spotted an advert for a workshop run by writer Hanif Kureishi at the Royal Court. When she discovered she was better at reading out the plays than writing them, she applied for Rada. After graduating, she landed roles with the RSC, The Young Vic and the National, where her 1999 performance in Trevor Nunn's Troilus and Cressida attracted rave reviews.

Dirty Pretty Things was her first movie and she is tremendously proud of the film. 'It's a great London story and had lots of parts for mostly non-white people! You came out looking at everyone differently. There are so many refugees in London. God knows what their story is. When people start moaning about, you know, five families living next door to them, you think "You have no idea what they've been through".' She is appalled by politicians from left to right playing the immigration card. 'Like we haven't got enough to share with everybody in the West!'

Did she have any reservations about playing a prostitute (Cathy Tyson found herself typecast after Mona Lisa)? 'Stephen told me later that Hanif said to him, "You can't ask Sophie to play the black prostitute!" And I said, "You can tell Hanif to fuck off, I want to play it!" I just thought she was a great character. I wasn't thinking about my colour at that point. In fact, I met a few women to research her, and none of them was black. They were all eastern European, so I was a bit of a rarity.'

Okonedo has been quoted as saying that while growing up she experienced racism from the Jewish community for being black and from the black community for being Jewish. While she doesn't deny her childhood was character-building, she has never made a public statement about it. 'The only thing I can think of is there was a journalist who used to work for The Jewish Chronicle about eight years ago. I did a tiny piece for them, and we often chatted off the record about things after the theatre. I can only think it came from that.'

In fact, Okonedo seems remarkably sane. She admits she battles with guilt for enjoying her work so much. 'You think, ooh, I must be slapped down, naughty girl. We should all live in America - they don't feel guilty about anything.' Why does she love performing? 'You feel very live and present in the moment - I wish I could carry that into my real life. I listen much better when I'm acting than I do in real life.'

She plans to relax more and spend time with her daughter, Aoife, from her relationship with Irish film editor Eoin Martin. They no longer live together. 'I don't have a partner,' she says coolly. Then, worrying that she has been unfriendly, adds, 'One paper wrote that I was married with two children. A friend who hasn't seen me for six months sent me an e-mail saying, "Goodness, you've kept yourself busy!"'

She is holding out for another great project after Hotel Rwanda. 'When I do things that aren't very good, I'm worse as an actor. I don't know what I pick up - but it's something not very nice.' She has a passion for new writing and sits on the board of directors of the Royal Court. 'I don't like going for more than a year without doing theatre. I don't mind falling flat on my face so long as I feel I'm open to the possibility of something extraordinary happening.'

In the meantime, Channel 4 is rushing out Born With Two Mothers, a docu-drama about an embryo mix-up between a black and a white couple, in which she stars with Lennie James. 'I'd hate to lose the character actress part of me, because, by God, the parts are much more interesting. As a black actress all I was offered in British film was the best friend role, whereas in TV I was offered a whole spectrum of parts. I'd love to be able to follow that through into my newly-formed film career which I didn't expect to get at 36!'

I suggest that the most interesting catalyst for drama today is the 35 to 55-year-old woman. 'Definitely, it's certainly where my life's become more interesting,' Okonedo cackles. 'I'm drawn to stories about ordinary people who get tangled up in an extraordinary event or idea or emotion. I'm not saying I don't love films about super-people or super-doctors, but my preference is for stories about how we get through this life, what it is to be human, because I'm always struggling with it myself.'

Just occasionally, the glitzy hooplah of the Oscars makes sense when it throws up a genuine outsider - someone like Okonedo or Jean-Baptiste or Brenda Blethyn who has slogged away as a jobbing actress for years. Frears puts it more succinctly: 'Sophie being nominated has just made life worth living. She's just sublime, really.'